1
Electromagnetic Stealth: The Fight
Against Radar
Justin Wilson
Abstract— During WWII, radar and surface to air missiles
posed an increasing threat to aircraft. It was at this time that
stealth technology became an important topic of investigation.
This paper will discuss the historical points that have lead to the
rise of stealth technology. It will also discuss the different types
of stealth technology and how they apply to electromagnetics.
After a better understanding of stealth technology is acquired,
new radar systems will be investigated including a possible
breakdown of stealth technology on the B-2 stealth bomber. This
paper will then conclude with the moral implications of using and
designing stealth technology.
Index Terms— Stealth, Low Observable, Radar
I. HISTORY
n the late 1930’s and early 1940’s radar technology was
becoming increasingly used to detect aircraft. During
WWII, Germany, France, Great Britain, and the United States
all used this technology to navigate ships and aircraft and to
detect approaching enemy aircraft. Radar itself did not pose a
direct threat to the United States though because the radar
technology was never integrated into the anti-aircraft defenses.
This all changed for the United States and its allies during the
Vietnam and Yom Kipper wars [1]. The United States needed
to develop a way of evading radar in order to make its fleet of
aircraft safer and more effective.
I
of propagating waves, including light. Someone hearing their
own voice is an example of sound waves hitting a surface and
then reflecting straight back at them. A mirror is an example
of light waves being reflected back at one’s self. Light from
an external source hits a body and bounces off in several
directions. Some light waves propagate towards the mirror
and then reflect off of the mirror back to that person’s eyes.
This same exact principle applies to radio waves. Radio
waves are simply non-visible forms of light. The idea behind
radar is to transmit a radio wave and then receive the
reflection from an aircraft. The amount of time between the
transmission and the reception can be used with a very
accurate number for the speed of light to determine how far
away the plane is from the radar station.
B. The Doppler Shift
The second principle that is used in radar is the Doppler Shift.
One familiar case of Doppler Shift that will help to explain
what it is and how it can be used in radar is that of an
ambulance or car with its sirens or horn on. The sound that
you hear as the vehicle is approaching you is at a higher pitch,
or higher frequency, than the sound you hear when the vehicle
is moving farther away from you, see Figure 1.
In the late 70’s, two prototype planes were built to study and
test low observable, better known as stealth, technology. The
entire project was incredibly secret and only a handful of
people knew the full potential of this technology. The two
prototypes lead to the introduction of the F-117A which was
fully operational in 1983 and then used in Operation Just
Cause (Panama) in 1989 [2].
After the success of the F-117A, the United States Air Force
has expanded their fleet of stealthy aircraft such as the B-1 and
B-2 bombers, the F-22, and the F-35 [3]. Stealth technology is
still being studied extensively and there are probably several
highly classified projects going on right now that no one is
aware of.
II. THE BASICS OF RADAR
A. Echo
There are two basic principles that are useful to understand
before discussing how radar technology is used. The first of
these principles is echo. Many understand an echo to be
someone’s voice bouncing off of something and coming back
to them. This is a very accurate definition of what an echo is
but it can be taken in a more broad sense to include all types
Figure 1: Audio Example of Doppler Shift [4]
This can be explained with the following example presented
by [4]: “Imagine that the car is standing still, it is exactly 1
mile away from you and it toots its horn for exactly one
minute. The sound waves from the horn will propagate from
the car toward you at a rate of 600 mph. What you will hear is
a six-second delay (while the sound travels 1 mile at 600 mph)
followed by exactly one minute's worth of sound. Now let's
say that the car is moving toward you at 60 mph. It starts from
a mile away and toots it's horn for exactly one minute. You
will still hear the six-second delay. However, the sound will
only play for 54 seconds. That's because the car will be right
next to you after one minute, and the sound at the end of the
minute gets to you instantaneously. The car (from the driver's
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perspective) is still blaring its horn for one minute. Because
the car is moving, however, the minute's worth of sound gets
packed into 54 seconds from your perspective. The same
number of sound waves are packed into a smaller amount of
time. Therefore, their frequency is increased, and the horn's
tone sounds higher to you. As the car passes you and moves
away, the process is reversed and the sound expands to fill
more time. Therefore, the tone is lower.”
One may ask, ‘How can this principle be used in radar?’ This
Doppler shift can determine how fast an object is moving. In
radar, the transmitted radio wave discussed earlier is sent at a
known frequency. When the reflection is received, its
frequency will be smaller, larger, or the same as the
transmitted radio wave. If the reflection is the same frequency
then the object isn’t moving, such as a helicopter hovering in
one spot. If the reflection is at a higher frequency, then it is
moving towards the radar tower and the amount of increase in
frequency can be used to determine how fast it is moving
towards the radar tower. The same is true with a lower
frequency reflection but in this case, the object is moving
away from the radar tower.
C. Why Radio Waves
If the principles of echo and Doppler Shift are used together in
radar systems, then radar would be able to detect the location
and the speed of an aircraft. The previous examples used to
describe these principles used sound waves. In contrast, radar
uses electro-magnetic waves instead of sound waves. There
are several reasons for this. The first is that sound waves
cannot travel as far as light without significant attenuation.
Secondly, electromagnetic echo is much easier to detect than a
sound echo.
D. The Radar Cross Section
There are multiple characteristics that determine the range of
radar systems. These variables are the peak transmitted
power, wavelength of the system, a loss factor, the power of
the noise within the receivers bandwidth, the ratio of the
received echo to the amount of noise, and the radar cross
section. The radar cross section (RCS) is the only factor that
is controllable by the designers of the object under detection.
For this reason, stealth designers seek to minimize the RCS of
an aircraft.
RCS [m2]
Object
F-15 Eagle
405
B-1A
10
SR-71 Blackbird
0.014
Birds
0.01
F-22 Raptor
0.0065
F-117
Nighthawk
0.003
B-2 Spirit
0.0014
Insects
0.001
E. Applications of Radar
Radar has many uses in both military and civilian applications.
In the military, radar is used to detect enemy aircraft and to
guide friendly aircraft. The military also uses radar to detect
above surface water vessels. Radar can also be integrated into
anti-aircraft defense systems to enable anti-aircraft artillery to
be more accurate. Radar can also be used to guide missiles to
determine if they are on the correct path. In civilian
applications, radar is used in air traffic control rooms and
police use radar to determine if a vehicle is traveling to fast.
Radar is also used to map out geographical locations and to
observe the movement of objects in space such as planets,
satellites, and debris. Another application of radar is in
predicting sort-term weather patterns such as rain,
thunderstorms and even tornados.
There are many other
applications of radar that I have not listed but from this list it
is obvious that the world would be a very different place
without radar.
III. STEALTH TECHNOLOGY
A. The Need for Stealth
There is one application of radar that pushed stealth
technology into existence. That application is of the radar
guided anti-aircraft systems. There are several different
varieties to these systems. One system is to guide a turret to
hit an enemy aircraft with a bullet. Such a system is shown in
Figure 2.
IN ORDER TO UNDERSTAND STEALTH TECHNOLOGIES IT IS HELPFUL TO
UNDERSTAND HOW THE RADAR CROSS SECTION IS CALCULATED AND WHAT IT
MEANS. ACCORDING TO [5], “THE RADAR CROSS SECTION MAY BE
CONSIDERED AS THE PROJECTED AREA OF AN EQUIVALENT REFLECTOR WHICH
HAS UNIFORM PROPERTIES IN ALL DIRECTIONS. THIS EQUIVALENT REFLECTOR
IS A SPHERE WHICH WILL RETURN THE SAME POWER PER UNIT SOLID ANGLE
(STERADIAN) AS THE AIRCRAFT.” WITH A SPHERE, THE ASPECT ANGLE OF THE
RADAR DOES NOT AFFECT THE AMOUNT OF ECHO ENERGY THAT IS RECEIVED.
THUS, THE ENERGY RECEIVED FROM AN AIRCRAFT’S ECHO, AT A GIVEN
ASPECT ANGLE, IS COMPARED TO THE SURFACE AREA OF A SPHERE THAT WILL
PRODUCE THE SAME AMOUNT OF REFLECTED ENERGY.
Table 1 compares the typical RCS values of birds and insects
to typical RCS values of military aircraft.
TABLE 1
RCS OF VARIOUS FLYING OBJECTS [6]
Figure 2: Anti-Aircraft Turret
Another system is to fire radar fused shells into the air. These
shells emit their own radar signal and then determine the
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distance to planes around it. When it is close enough to a
plane it explodes launching fragments in every direction.
With these two types of systems, it became very dangerous to
use aircraft to penetrate an enemy controlled area. The
response to this deadly form of radar technology was stealth.
Simply put, stealth makes it difficult for radar to detect the
presence of an object in the air.
Figure 4: Diffuse Reflection
B. Shape of Aircraft
The overall shape of an aircraft can play a significant role in
reducing its radar cross-section (RCS). Research into this
form of stealth technology was the first to surface. The design
of the shape of the aircraft is highly dependent on the type of
materials that are used for the construction of the plane.
Designs of the 1960’s and 1970’s used conductive materials,
while designs of today use non-conductive, composite
materials.
1) Conductive Material Design
According to [1], Denys Overholser created a software
program called EHCO 1, while he was working at LockheedMartin in the late 1960’s. EHCO 1 used equations to simulate
how electromagnetic waves reflect and scatter off of 3dimensional conductive objects. These calculations and
simulations were limited to flat panels and thus determined
that a diamond shaped object would reduce the object RCS
best [1]. This is why the earlier stealth planes such as the
F117-A and the Have Blue prototypes used faceted flat panel
designs. The theory behind the calculations is actually quite
simple. Using the law of reflection and geometry we can
determine why the diamond shape works best. The law of
reflection is easy to demonstrate using a mirror and laser as
shown in Figure 3.
Figure 3: Specular Law of Reflection
The ray from the laser source is called the incident ray and it is
labeled with an ‘I’. The reflected ray is labeled with an ‘R’.
The angle formed between the normal and the incident ray is
equal to the angle between the normal and the reflected ray.
This type of reflection is called specular reflection.
Reflections can also be scattered over a larger range of angles.
This form of reflection is called diffuse scattering and is
shown in Figure 4. Specular reflection occurs when the
surface of reflection is flat and smooth (relative to the
wavelength of the incident ray). Diffuse reflection occurs
when the object has small abrasions or inconsistencies. In
order for radar to be effective, the reflected ray must be
directed along the same path as the incident ray.
For flat, smooth objects the incident ray must be
perpendicular, or normal, with the surface it is reflecting off of
for radar to work. For rough surfaces, a portion of the incident
ray would be directed back from any direction.
For
aeronautical applications, it is safe to assume that the surface
will be smooth because un-smooth surfaces would have poor
aerodynamic properties. With this assumption we will
elaborate on spectral reflection. Take, for example, a large
commercial aircraft, shown in Figure 5.
Figure 5: Front of 747
With curved objects, there are infinite tangent lines and thus,
an infinite number of normal lines. With infinite tangent lines
more radar signals are directed back to the radar antenna. This
makes commercial aircraft easy to detect using radar. On the
other hand, the first prototype stealth planes featured a
diamond shape. This diamond shaped aircraft is composed of
flat surfaces and there are a limited number of normal lines in
which radar signals can be projected back on. Figure 6
illustrates how radar signals are redirected away from the
aircraft and away from the radar antenna.
Figure 6: Redirected Radio Waves [2]
The aircraft shown is an F117-A that was designed in the 70’s
and made known to the public in 1988.There are a few
unfortunate consequences of a design as shown in Figure 6.
The first, and major, disadvantage is that the aircraft that is
designed with these flat surfaces have poor aerodynamics and
lack agility, which is important for fighter aircraft. A second
disadvantage to this shaping is in its ability to actually
decrease the radar cross section of the aircraft. While this is a
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very good way to reduce the RCS of the aircraft for
monostatic radar systems (radar systems in which the transmit
antenna and receiver antenna are the same antenna), this
shaping poorly reduces the RCS of the aircraft for bistatic
radar systems (radar systems in which the transmit and receive
antennas are separated by a large distance. If multiple
receptors are used, then a reflection can be picked up by
another radar station, different from the source, and the plane
can be detected in that way. These disadvantages have lead to
the development of different types of materials to build stealth
planes with. These composite, non-conductive materials are
used in the B-2 and F-22, allowing them to be more
aerodynamic.
2) Non-Conductive Material Design
Composite materials were first used on the U2 spy plane
which flew at altitudes of 80,000 feet. The composite
materials and the flying altitude made it very difficult for radar
systems of the 1950’s and 1960’s to detect the planes. The
same is true today of composite materials but additional
methods of stealth are used with the composite materials (such
as absorbent paint, see section III. C. ).
In composite materials, the amount of energy that is reflected
from an incident radar signal is highly dependant on the
dielectric constants of the composite material and the air, the
incident angle, and the polarization. The first of these
properties can be controlled by the designer of the aircraft but
the second and third property cannot.
The following
equations, taken from [7], are useful in understanding how to
choose the composite material properties.
 
 
n 1 cos   1
n 2 cos   2
n 1 sin  1
n 1p
n 2p
n 2 sin  2
( 1)
( 2)
( 3)
Equation ( 1) is called Snell’s Law of Refraction and it simply
states the relationship between the reflected angle, and the
transmitted angle, (all angles with respect to the
normal)Similar to the conductor case, the reflection angle is
the same as the incident angle. Equations ( 2) and ( 3) are
used to find the effective impedances valid for p-polarization
waves. Similar equations exist for the effective impedances of
the s-polarization waves, which use the secant of the angle
instead of the cosine.
s
p
n 2s  n 1s
n 2s  n 1s
n 2p  n 1p
n 2p  n 1p
fraction of the incident power that is reflected and transmitted.
Pr
P inc
Pt
P inc

1
p

2
p
2
( 6)
( 7)
To minimize the reflected power, the design must minimize
the effective impedance of the material. This is done by
matching the dielectric constants of the material and air as
closely as possible. When n1 = n2, 1 and 2 are equal, n1s
equals n2s, and n1p equals n2p. This means that the effective
reflection impedances are zero for both the s and ppolarizations, independent of . One concern with composite
materials is that the transmitted ray will eventually hit
something that will reflect the wave. One method of dealing
with this reflection is to make the composite material also
absorbent material. This technology is similar to absorbent
paint which will be discussed in section III. C.
3) Other Shape Considerations
In addition to the overall shape of this aircraft, there are a few
other considerations that will help reduce the RCS of an
aircraft. First, almost all stealth aircraft have their payload
mounted inside the plane. Bombs and machine guns are not
exposed and are stored inside the wings or center of the plane
and only appear for brief moments while firing or releasing.
Also, all landing gear is kept inside the plane. Second, the
overall size of the aircraft should be relatively small. Third,
vertical surfaces towards the rear of the plane are often angled
in to reduce the chance of radar being incident at a 90-degree
angle. Forth, reflective coatings are painted onto the cockpit
so that radar beams reflect away from the aircraft instead of
hitting objects inside the cockpit. Often objects inside the
cockpit are odd shaped and difficult to make stealthy. These
objects would stand out like a beacon if the glass were not
coated with some sort of reflective paint. The last general
consideration to make in the aircraft’s design is to minimize
intake cavities. Intake cavities make it impossible to reduce
the radar reflections from the object inside of the cavity as
shown in Figure 7.
( 4)
Figure 7: Straight Cavity
( 5)
Equations ( 4) and ( 5) are used to find the reflection
coefficients for s and p-polarizations, respectively. These
values are then used in equations ( 6) and ( 7), to find the
With respect to the engine, these cavities make highly
reflective turbine blades visible to radar, which causes a
significant increase in the RCS of the aircraft. Often, engine
intakes incorporate an S-shaped duct, as seen in Figure 8, so
that the turbine blades are not visible to radar.
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compromised. The F117A Nighthawk fleet is in the process
of being refurbished right now and a special robot is being
used to apply the coating. Without the robot it would take a
team of 5 painters 4.5 days to paint one F117A Nighthawk [9].
Also, after each mission, the planes need to be inspected to
determine that the paint is holding up to specifications. This
testing increases the amount of time that the jet is inoperable.
However, these disadvantages are currently determined to be a
good trade off with the performance of the RAM coatings and
thus it is widely used to achieve a significantly smaller radar
cross section.
Figure 8: S-Shaped Cavity
Another method of reducing the effect from the turbine blades
is to use absorbent paint. As of now, absorbent paint that can
meet the demands of the turbine environment is very costly.
C. Absorbent Paint
Radar absorbent material (RAM) is probably the most
common technology used to reduce an aircrafts RCS. An
equivalent optical example would be black paint. An object
that is painted black absorbs all the light that hits it (black is
the absence of reflected light hitting your eyes). The idea
behind RAM paint is to absorb the energy of the radio waves
transmitted by the radar antenna. RAM contains carbonyl iron
ferrite as the active ingredient. When radar waves hit the
RAM coating a magnetic field is produced in the metallic
elements of the coating. The magnetic field has alternating
polarity and dissipates the energy of the signal. The energy
that is not dissipated by the individual carbonyl iron ferrite
elements is reflected to other elements as shown in Figure 9.
Figure 9: Incident Radar Beam Dissipated in RAM Coating
The majority of this energy is dissipated in the form of heat
[8]. The use of RAM coating is very effective but there are
some drawbacks to this technology. First, the RAM coating is
highly toxic. In hangers containing aircraft with RAM
coatings, bats have fallen from the ceiling because of the
accumulation of toxic fumes in the hanger. The second
problem is that the aircraft looses some aerodynamic
properties because of the paint, which causes additional heat
problems. The third problem with RAM coatings is the
expense. Applying the paint is a very time consuming
process. The paint must be applied at a specific thickness, no
bubbles can develop, and the surface of the plane cannot be
D. Active Radar Signal Cancellation
Some methods of reducing the RCS of an aircraft are not
practically achievable. Active radar signal cancellation is one
such method. Active signal cancellation is similar to active
noise cancellation so it may be easier to consider the audible
example of active signal cancellation. In active noise
reduction (ANR), a second audio speaker is used to create a
sound of equal magnitude but 180 degrees out of phase. The
two audio signals, the noise and the anti-noise, combine and
the result is theoretically zero. In active radar signal
cancellation, a radio wave receiver on the aircraft detects
incoming radar signals and then estimates the characteristics
of the reflected radio wave and attempts to cancel the reflected
radio wave with a second radio signal generated by the
aircraft. There are two main problems with this method of
stealth that make it impossible to implement. The first
problem is that radar signals are traveling at the speed of light,
which is must faster than the speed of sound. In essence, the
electronics used to calculate the canceling radar wave would
need to be able to compute the canceling radar wave faster
than the speed of light. This is impossible with today’s
technology. One suggested method of making this more
feasible, at least for ships, is to have multiple poles extending
from the surface. These poles would increase the amount of
time that the generated signal could be calculated. For
example, if the pole extended 20 meters from the ship’s
surface, it would have approximately 133ns to compute the
signal and generate it. The problem with this is that the poles
would have to employ a different type of stealth because they
will also be detected by the radar station. There is a second
problem with active radar signal cancellation that this
suggested fix does not account for. In active noise reduction,
an error microphone is used to determine how much error is
being generated in the act of canceling the audio wave. This
error microphone incorporates negative feedback to eliminate
the error and improve the noise reduction. With active radar
signal reduction such error calculations cannot be done
because of the lack of error detection. Therefore, the system is
open loop and any error generated cannot be corrected. If
active radar signal cancellation is ever used, it will be quite a
long time from now before it is feasible.
E. Plasma Stealth
Plasma stealth technology is the leading edge technology and
is still under considerable research. The motivation to use
plasma stealth is similar to that of radar absorbent materials.
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According to [3] and [10], electromagnetic waves have been
observed to be absorbed by or bend around plasma fields for
decades. If a plasma cloud could be created around the
outside of an aircraft, electromagnetic waves would be
absorbed by the stealth instead of reflecting back to the radar
antenna.
around the cloud and past the aircraft. This, however, is
minimal in decreasing the RCS of an aircraft. According to
Halerewicz in [12], a more feasible way of reducing the RCS
is to use the frequency oscillations of the plasma to change the
frequency of the incoming radar waves. This change in
frequency would cause the radar waves to become useless.
Plasma stealth technology has three major advantages. The
first is that the RAM painting is not necessary when a plasma
cloud is used. This means that the cost and maintenance of
RAM coatings are avoided. Second, plasma clouds also
provide a heat shield that separates the plane from super
heated air [3]. Lastly, the plasma cloud would smoothen
airflow across the fuselage of the aircraft making it more
aerodynamic[3].
Figure 10: A Familiar Form of Plasma
Before discussing the advantages, disadvantages, and
feasibility of this technology, let us first discuss what plasma
is and some of its other applications. In normal gases, each
atom is electrically neutral. It is composed of equal number of
protons and neutrons. If this gas is heated up enough, one or
more electrons from the gas atoms will release from the pull of
the nucleus, causing the atoms to be ionized. If this process
happens to a significant number of gas atoms in a given
volume, that gas becomes plasma. For this reason, plasma is
often called the fourth state of matter. Because a significant
amount of the gas is electrically charged, the electrical
properties of the plasma behave differently than the properties
of the gas. In most cases the ratio of neutral and ionized
atoms determine the behavior and usefulness of the plasma
[11]. There are two forms of plasma that are quite common on
earth, fire and lightning, but plasmas are also used in water
purification, synthesis of ceramic powders, lasers, propulsion,
and plasma displays.
As mentioned previously, the plasma aids in absorbing the
radar signals.
The absorption takes place when the
electromagnetic waves encounter a charged particle. During
this encounter, a portion of the electromagnetic wave’s energy
is transferred to the charged particles. This effect can be
explained better using a somewhat related example.
Microwave ovens work by emitting an electromagnetic wave
with a frequency that causes water particles to vibrate. In this
case, the water absorbs the electromagnetic energy and heats
up the water. Similarly, if one were to put a lit candle into a
microwave, the flame would absorb the energy from the
candle (the result is quite interesting but I wouldn’t
recommend doing this if you value your microwave and/or
your home).
Another interesting result of a plasma cloud around an aircraft
is that electromagnetic waves, or radar waves, tend to bend
There are a few disadvantages to plasma stealth technology
that are currently being researched. The first problem is
creating the plasma cloud. One suggestion, which has been
posted on [3], is to have some sort of energy source on the
leading edge of the plane that would ionize the air. Since the
air will flow along the plane anyway, the ionized gas will then
follow the planes surface and coat it entirely. Then, on the tail
of the plane, you would charge it opposite of the leading edge
to neutralize the plasma. The rest of the plane would need to
be insulated so that the plasma didn’t neutralize until the tail
of the plane. One such plasma generator was developed in
1999 by the Keldysh Scientific Research Center. The plasma
generator only weighed 100kg but used power on the order of
megawatts [13][14]. One solution for the high power
requirement is to only use the device when absolutely
necessary. A second solution is similar and more practical.
Several smaller plasma generators would operate for different
locations on the plane. And thus, only sections that detect
enemy radar signals will generate a plasma field.
The second shortcoming with plasma stealth technology is that
the plasma layer that would surround the plane would also
block the pilot’s radar. According to [13], the designers of the
Russian SU-35 tested a plasma generator similar to the one
mentioned previously. In this model the generator switched
frequently to let its own radar out at a set interval. Probably
the best solution to this problem is to use a different type of
stealth technology on the antenna itself and eliminate the
presence of plasma around the radar antenna.
The third drawback is that when the ions neutralize they will
give off light and not all ions will neutralize either. These left
over ions will neutralize later creating a visible path that
points directly to the plane. This visual path is called a plasma
trail and can also be used to lock on planes but this can be
overcome by either flying very high or by operating only
during the day. Figure 11 shows the plasma trail left by the
space shuttle Columbia shortly before the tragic events of
February 1, 2003. The plasma trail shown is normal to space
shuttle reentry. It is caused by the super heating of air around
the space shuttle which ionizes the surrounding gas. This gas
then neutralizes behind the space shuttle and gives off light.
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Figure 11: Columbia Plasma Trail
Disadvantages aside, this exact technology is being
implemented in the Russian “AJAX” hypersonic aircraft
project [3]. How the Russian plasma generator works is a
secret that will not be published for quite some time but there
have been some guesses posted on internet discussion boards.
One person speculates that an electromagnetic field should be
generated. But this may be a problem as well because the
electromagnetic field could be detected. Another suggests
using a corona source that continuously breaks down or a
pulsing tesla coil (which would in turn produce an EM field).
Another suggestion is a plasma laser. A common problem
with each of these sources is that they are often very large and
use a large amount of power.
I think that considerable improvements can be made to plasma
stealth technology. I also think that with a few years of
research in this area and quite a bit of money most if not all of
the shortcomings of plasma stealth technology will be solved.
When this happens the advantages will leave RAM coatings
and bulky flat panel, poor aerodynamic designs in the past.
IV. THE FIGHT AGAINST STEALTH
After stealth technology became quite effective, radar
technology began to improve as well. New radar technology
is currently being researched that will cause current stealth
capabilities to become obsolete.
It is well known that older short-wave radar technology used
by Russia is able to detect stealthy aircraft considerably better
than long-wave radar. Fortunately for stealth technology, all
surface-to-air weaponry is based on long-wave radar so the
systems cannot be combined to provide devastating results.
The devastating results come from the Czech Republic. In the
early 1990’s, a company in the Czech Republic was able to
design a new detection device called the Tamara. The Tamara
is a complex system that receives large numbers of signals at
any given time. The basic method of detection is to look for
signals emitted from the stealthy aircraft. Even though the
aircraft can significantly reduce the amount of electromagnetic
energy that reflects off of it, it cannot reduce its own
emissions as well. So just how effective is the Tamara
detection system?
At this point, things begin to get quite political. In 1999, an
F117-A was shot down over Yugoslavia. This also happened
to be the first F117-A to be brought down in combat since
their introduction in the 1980’s. Did this happen because of
the Tamara? At the time, the media speculated that it was
indeed the Tamara system that was used to detect the stealth
craft. The U.S. government does not go this far though. They
do not give any credit to the Tamara system and they say that
its effectiveness is not much better than a standard radar
system. They blame the incident on flight plans being leaked
from NATO meetings. The government claims that the plane
was easier tracked because the tracker already knew where it
was going to be and when it was going to be there. So, with
the government so adamant about the Tamara not being
effective, what grounds can one use to defend the Tamara
system? Well, it is quite interesting that Russia, China, and
Iraq have all tried to get their hands on it in one way or
another. That must mean that there is something special about
it. Also, the United States did everything in its power to make
sure that the above countries were not able to get the system.
Again, the politics cloud the issue, but I would have to say that
there is some validity to the effectiveness of the Tamara
system.
Another system that could effectively make American stealth
technology obsolete is currently being worked on and there
isn’t very much information on it. The theory behind this new
detection system is quite simple though. Present day radar
systems send an electromagnetic system into the air and then
wait for a response, as described previously. These new
detection systems will send signals from above the target and
wait for a reply. If there is not a reply, that means that
something stealthy has absorbed the emitted signal! The
system may be an aircraft that flies over the earth scanning the
ground looking for “blank” spots or it may be in the form of
satellites doing the same thing. Another way that this idea
could be carried out is by using the electromagnetic emissions
of stars to determine where aircraft are from the ground.
These ground-based systems would scan the sky for aircraft by
noticing if certain stars are not visible or if their radio
emissions are dimmer than normally. According to [15],
virtually the entire sky is covered with radio emissions from
stars. This “radio map” is well known and can be used to
compare to collected data. The disadvantage to the system of
checking for “blank” spots is that the amount of computer
computations needed is quite large. The system is very good
at tracking planes once the target has been identified, but it is
does not find objects as quickly as a conventional radar. The
reason for this is that the system must scan a large area and
then compare that total area to a known value. Depending on
the resolution and the area covered, which can be a very large
number of comparisons.
V. ETHICAL CONSIDERATIONS
For this section there are a few questions that I would like to
ask the reader. These questions apply both to Christians and
non-Christians. I will give my own thoughts one each
question but I urge you to come to your own conclusions.
8
First, is stealth technology more prone to being used for evil
or for good? This question largely depends on what one
defines to be evil. Is it evil to destroy terrorist buildings if
there aren’t any people inside? Is it evil to destroy terrorist
buildings if there are people inside? Is it evil to destroy
communications buildings if no one is there? Is it evil to
destroy them if someone is there? Is it evil to destroy
hospitals, market places, community centers, and housing
developments? The odds are that the answer to at least one of
these questions was yes. Some readers may even be able to
give a convincing argument for saying yes to each of these
questions. The truth to the mater is that stealth technology
allows air forces to do all of the above without any warning
being given to the targets. What good can come out of stealth
technology? For one, thousands of pilots for the United States
have returned from missions unharmed because of stealth
technology. That certainly is a good thing. Above surface
ships use stealth to protect the thousands of Americans
onboard from enemy attack. That certainly is a good thing.
My second question is, “Let us assume that stealth technology
is used for more evil than it is for good, is it morally right to
design this technology?” There are probably very few people
who would answer this question exactly the same. I believe
the reason for a large number of different answers stems from
the fact that this question is somewhat of a gray area or a
“disputable matter.” Roman’s 14 speaks about such matters.
Paul says this with regards to disputable matters, “Each one
should be fully convinced in his own mind.” Specifically, he
states with regard to clean and unclean food (a spiritual
matter), “I am fully convinced that no food is unclean in itself.
But if anyone regards something as unclean, then for him it is
unclean.” From this chapter in Romans I have come to a
conclusion about the morality of stealth technology and
designing it. Christian designers of stealth technology, and
any other technology for that matter, must be fully convinced
that what they are doing is in accordance with God’s will, for
each of us will give an account of himself to God. All
technology can be used for good or for evil and this simple
truth must be realized in the design process. All designers,
Christian and non-Christians alike, should consider the uses of
their design and if possible make design changes that help
prevent the design from being used for evil.
VI. CONCLUDING REMARKS
Radar and stealth technologies have become significantly
more advanced in the last fifty years and this trend will
continue because the two technologies are against each other.
It is somewhat of an arms race except it isn’t between specific
countries. It is a fight between technologies.
VII. RESOURCES
[1]
[2]
[3]
Deep Black: Stealth Technology F-117 B-2 Combat Performance
Tactics. [Online] <http://www.danshistory.com/stealth.shtml>.
Stealth Technology - Low Observable Aircraft. [Online}
<http://www.lowobservable.com>.
Plasma Stealth Technology. (August 4, 2002). [Online]
<http://www.aeronautics.ru/plasmamain.htm>.
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
Brian, Marshall. Howstuffworks “How Radar Works.” [Online]
<http://electronics.howstuffworks.com/radar1.htm>.
Howe, D. Introduction to the Basic Technology of Stealth Aircraft: Part
2-Illumination By the Enemy - (Active Considerations). The American
Society of Mechanical Engineers. June 11-14, 1990.
Aerospaceweb.org | Q and A -Radar Cross Section. [Online]
<http://www.aerospaceweb.org/question/electronics/q0168.shtml>.
Hayt, W. H., Buck, J. A., Engineering Electromagnetics, 6th ed.,
McGraw-Hill, 1958.
How “Stealth” is Achieved on F-117A. [Online]
<http://www.aeronautics.ru/f117a.htm>.
Painting the Stealth. [Online] <http://www.sandia.gov/isrc/F117.html>.
www.Air-Attack.com--->Plasma Stealth Technology. [Online]
<http://www.air-attack.com/page.php?pid=19>.
Coalition for Plasma Science - What is a Plasma? [Online]
<http://www.plasmacoalition.org/what.htm>.
An Exchange and Critique of the Various Mechanisms Which are
Incorporated in UNITEL’s Stealth, Propulsion, and Macroscopic
Quantum Tunneling Concepts. [Online]
<http://www.stealthskater.com/Documents/UNITEL_10.doc>.
Stealth Design SU-35. [Online]
<http://home.iae.nl/users/wbergmns/stealth2.htm>.
Plasma Stealth Device Suspected on MFI. [Online]
<http://www.aeronautics.ru/mfiarticleafm3.htm>.
Mehta, Cyrus and Mehta, Ardeshir. Anit-Stealth Technology. December
15, 1998. [Online] <http://homepage.mac.com/ardeshir/AntiStealthTechnology.pdf>.